An agricultural spreader is a machine that spreads granular materials such as fertilizer, sand, manure, lime, chemicals, etc. Government regulations and natural market forces both encourage farmers to spread material precisely. The concentration of material applied to a farm field affects compliance with environmental rules, for example. A dairy cow can generate over 100 pounds of manure per day (although. Jerseys make less than Holsteins) and farmers must make sure that spreaders disburse the manure such that acceptable levels of nitrogen, ammonia, nitrate, phosphorus, antibiotics, pesticides, hormones, etc., are not exceeded.
In addition, profit-seeking farmers naturally try to use raw materials as efficiently as possible. Spreading too much fertilizer, for example, wastes money. Unfortunately, conventional spreading equipment lacks an accurate way to measure how much material is spread per unit time or per unit area. Mechanisms exist to vary spreading rate, but they operate open-loop; there is no way to monitor results. Thus, what is needed is an agricultural spreader control system capable of measuring and controlling the spreading rate of a spreader.